The present invention generally relates to rotary recording medium reproducing apparatuses capable of performing special reproduction, and more particularly to a rotary recording medium reproducing apparatus capable of changing over and selecting a plurality of predetermined changed speed reproduction speed by simple switching operation.
A new information signal recording and/or reproducing system has been proposed in a United States Patent Application Ser. No. 785,095 entitled "INFORMATION SIGNAL RECORDING SYSTEM" filed Apr. 6, 1977, now U.S. Pat. No. 4,331,976, of which the assignee is the same as that of the present application. According to this proposed system, the recording system forms pits in accordance with the information signal being recorded along a spiral track on a flat disc shaped recording medium (hereinafter referred to as disc), without forming a groove therein. In this reproducing system, a reproducing stylus traces over along this track thereby to reproduce the recorded information signal in response to variations in the electrostatic capacitance.
In this system, since a groove for guiding the reproducing stylus is not provided on the disc, pilot or reference signals should be recorded on or in the vicinity of a track of the information signal, such as a video signal, on the disc. Upon reproduction, the reference signals are reproduced together with the video signal. Tracking servo control is carried out so that the reproducing stylus accurately traces along the track in response to the reproduced reference signals.
By the use of this previously proposed system, there is no possibility whatsoever of the reproducing stylus or the disc being damaged since the recording track has no groove. The stylus can trace the same portion of the track repeatedly many times, whereby a special reproduction such as still, slow-motion, or quick-motion reproduction becomes possible.
Thus, in a United States Patent Application Ser. No. 4,813 entitled "SPECIAL REPRODUCING SYSTEM IN AN APPARATUS FOR REPRODUCING VIDEO SIGNALS FROM A ROTARY RECORDING MEDIUM" filed Jan. 19, 1979, now U.S. Pat. No. 4,340,907, of which the assignee is the same as that of the present application, a special reproducing system in a disc reproducing apparatus was proposed which is capable of performing a special reproduction in which a picture having a motion different from that upon normal reproduction is obtained in an excellent manner.
The special reproducing system comprises a reproducing element for tracing the track of the disc and picking up the recorded signal, a tracking control mechanism for operating in response to kick pulses applied thereto to cause the reproducing element to shift to an adjacent track turn of the spiral track, and a kick pulse generating circuit for generating kick pulses with timings corresponding to the vertical blanking period positions of the recorded video signal, where the kick pulses are of a number corresponding to an operational mode for carrying out a special reproduction differing from normal reproduction at every rotational period of the rotary recording medium, and supplying the kick pulses to the tracking control mechanism. The reproducing element is shifted to an adjacent track turn within the vertical blanking period of the recorded video signal, by the tracking control mechanism responsive to the kick pulses.
Accordingly, the noise introduced when the reproducing element moves to an adjacent track does not appear in the picture, and a special reproduction such as still reproduction, slow-motion and quick-motion reproduction in the forward direction, and normal-speed, slow-motion, and quick-motion reproduction in the backward direction can be performed in which a fine picture is obtained.
However, in the conventional apparatus, manipulation switches were provided according to respective reproduction modes such as still reproduction, slow-motion reproduction of a predetermined speed ratio, and quick-motion reproduction of a predetermined speed ratio. Therefore, the arrangement on the manipulation panel became complex, and the manipulation switches were difficult to manipulate. Particularly when the number of predetermined speed ratios which are to be set is large, the number of manipulation switches increases, and the above described disadvantage becomes notable.
Moreover, operations are performed to move the reproducing stylus from the position where the reproducing stylus makes contact with the disc and stop at a position on the disc where a video signal of a desired picture content is recorded, within a short period of time, while monitoring the image in the reproduced picture screen. This kind of operation was very difficult to perform by use of the above described conventional apparatus. In addition, there was a disadvantage in that the reproducing stylus could not be stopped accurately at the desired position on the disc.